New Jersey State House Dome

Trenton, New Jersey

The New Jersey State House has changed many times since its original construction to accommodate a growing state government. The current dome was designed by Lewis Broome in 1889 after a fire had ruined a smaller previous version. A complete restoration, for which Vertical Access coordinated all of the site investigations and safe access, was finished in 1999. The dome is constructed of gilded copper and cast iron supported by steel webbed columns and rises to 145 feet.

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Pre-restoration scope of work

  • Coordinated all scheduling of site investigations.
  • Performed close visual inspection of the interior and exterior of the cast iron drum/lantern and gilded, copper-clad dome.
  • Conducted non-destructive investigations using ultrasonic testing and fiber-optics borescope employed live video feed for interaction with subconsultants.
  • Coordinated subconsultant submissions to produce a four volume condition report, with annotated elevations, still photography, and video.

Building owner

The State of New Jersey

In collaboration with

Post-restoration scope of work

  • Performed close visual inspection of dome, drum, lantern, and cupola, documenting all fault conditions following a complete restoration in 1999.
  • Undertook borescope investigation of loose cast iron elements
  • Coordinated live feed video with collaborating architects.
  • Performed coating adhesion testing.
  • Performed ultrasonic thickness gauge readings of dome copper.

In collaboration with